Modern optical devices and optical communications systems widely use fiber optic cables. A typical fiber optic cable includes one or more optical fibers contained within a protective jacket. Reinforcing structures such as aramid yarns and/or fiber reinforced epoxy rods can be used to provide reinforcement to the optical cables. It is well understood that a typical optical fiber includes a glass fiber processed so that light beams transmitted through the glass fiber are subject to total internal reflection wherein a large fraction of the incident intensity of light directed into the fiber is received at the other end of the fiber. A typical optical fiber includes a glass core surrounded by a cladding layer having a lower refractive index as compared to the refractive index of the core. The cladding causes light to be confined to the core by total internal reflection at the boundary between the two. The cladding layer of an optical fiber is often covered by one or more polymeric coatings (e.g., acrylate) to protect the glass and to facilitate handling of the optical fiber.
Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Optical fiber connectors are an important part of most fiber optic communication systems. Fiber optic connectors allow two optical fibers to be quickly optically connected without requiring a fusion splice. Fiber optic connectors can be used to optically interconnect two lengths of optical fiber. Fiber optic connectors can also be used to interconnect lengths of optical fiber to passive and active equipment.
A typical fiber optic connector includes a ferrule assembly supported at a distal end of a connector housing. A spring is used to bias the ferrule assembly in a distal direction relative to the connector housing. The ferrule assembly includes a ferrule that functions to support an end portion of at least one optical fiber (in the case of a multi-fiber ferrule, the ends of multiple fibers are supported). The ferrule has a distal end face at which a polished end of the optical fiber is located. When two optical fibers are interconnected, the distal end faces of the ferrules abut one another and the ferrules are forced proximally relative to their respective connector housings against the bias of their respective springs. With the fiber optic connectors connected, their respective optical fibers are coaxially aligned such that the end faces of the optical fibers directly oppose one another. In this way, an optical signal can be transmitted from optical fiber to optical fiber through the aligned end faces of the optical fibers. For many fiber optic connector styles, alignment between two fiber optic connectors is provided through the use of an intermediate fiber optic adapter including an alignment sleeve that receives and coaxially aligns the ferrules of the fiber optic connectors desired to be interconnected. For certain styles of fiber optic connectors, the optical fibers are secured within their respective ferrules by a potting material such as epoxy. In other styles of fiber optic connectors, the optical fibers are free to slide axially relative to their corresponding ferrules.